Dynamic Model and Nonlinear Control for a Two Degrees of Freedom First Generation Tidal Energy Converter**This work has been partially supported by the Spanish Ministerio de Economía y Competitividad under Research Grant DPI2014-53499R and hiring of Miss Marina P. Portilla was funded by the GITERM research group from the Universidad Politecnica de Madrid.

Several manufacturers have developed devices with which to harness tidal/currents power in areas where the depth does not exceed 40 meters. These are the so-called first generation tidal energy converters (TEC). The maintenance tasks carried out on these devices therefore require them to be extracted from their bases to the sea surface and subsequently placed back on the bases. Special high performance ships are required for these tasks,...